They entered Tuesday's second-round game of the U.S. Open Cup coming off their first victory of the season. They were facing an inferior opponent, only needing a victory to secure a home game next week against Houston Dynamo of the MLS.

And with all of that as a tantalizing backdrop, the Scorpions fell flat on their faces at Toyota Field.

FC Tucson converted all four of its attempts and stunned the Scorpions 4-3 on penalty kicks after the game finished tied 2-2 after regulation and overtime.

A member of the USL Premier Development league's fourth division, FC Tucson plays the Dynamo May 29 in Houston.

“I would say it's more a case of we have professional players, they have amateur players,” Scorpions coach Tim Hankinson said after his team missed two penalty kicks in the extra session. “Tonight we played with amateur mentality. Our lack of intensity throughout the game was inexcusable. Our players should be ashamed of the performance they put in based on who they were playing.”

Coming off its first win of the year over the weekend, the Scorpions appeared as if they had turned a corner. That notion only gained steam when Kevin Harmse scored his first goal of the year, running into open space and heading in a pass from Walter Ramirez in the 16th minute.

FC Tucson, though, scored two goals only 10 minutes apart in the early stages of the second half to grab control.

The Scorpions pushed the game to overtime when Hans Denissen converted on a penalty kick in the 90th minute after FC Tucson was called for a handball in the penalty area.

FC Tucson recovered from giving up the late goal and survived a few tedious moments in overtime before prevailing on penalty kicks.

“You want to build on (your first win of the season),” Hankinson said. “We didn't build on that. We took a big step backward in a very important game. That's not just about football, that's also about the business of football. You lose a packed stadium against Houston Dynamo next week — which is an enormous piece of revenue for the club. We blew it.''